System and method for providing power saving mode enhancements in a network environment

ABSTRACT

A method is provided in one example embodiment and may include determining that a periodic timer for a user equipment (UE) is about to expire; communicating to an application service, prior to expiration of the periodic timer for the UE, an indication associated with an availability of the UE to receive data from the application service; and communicating the data from the application service to the UE upon receiving the indication. In some cases, the method can include registering, by the application service, to receive the indication from a Mobility Management Entity (MME) or a serving General Packet Radio Service (GPRS) support node (SGSN), wherein the registering is performed via a service capability exposure function (SCEF) in communication with the MME or the SGSN and the application service.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of priority under 35 U.S.C. §119(e)to U.S. Provisional Application Ser. No. 62/077,091, entitled “SYSTEMAND METHOD FOR PROVIDING POWER SAVING MODE CAPABILITIES IN A NETWORKENVIRONMENT” filed Nov. 7, 2014, which is hereby incorporated byreference in its entirety.

TECHNICAL FIELD

This disclosure relates in general to the field of communications and,more particularly, to a system and method for providing power savingmode (PSM) mode enhancements in a network environment.

BACKGROUND

Networking architectures have grown increasingly complex incommunications environments, particularly mobile wireless environments.Mobile communication networks have grown substantially in subscriberbase as end users become increasingly connected to mobile wirelessenvironments to conduct business, to shop, to interact with friends, tomaintain personal finances, and to perform many other daily functions.As the number of mobile subscribers increases, efficient management ofcommunication resources becomes more critical. In some instances, userequipment can be power saving mode (PSM) enabled, which allows the userequipment to conserve power resources while maintaining a connection tothe network. However, when in PSM mode, user equipment is unable toreceive traffic for mobile terminated services, which can cause suchtraffic to be rejected for delivery to the user equipment. Hence, thereare significant challenges in managing the delivery of traffic to PSMenabled user equipment.

BRIEF DESCRIPTION OF THE DRAWINGS

To provide a more complete understanding of the present disclosure andfeatures and advantages thereof, reference is made to the followingdescription, taken in conjunction with the accompanying figures, whereinlike reference numerals represent like parts, in which:

FIG. 1 is a simplified block diagram illustrating a communication systemto facilitate providing PSM enhancements in network environmentaccording to one embodiment of the present disclosure;

FIG. 2 is a simplified block diagram illustrating additional detailsassociated with one potential embodiment of the communication system;

FIGS. 3-4 are simplified flow diagrams illustrating possible exampledetails associated with the communication system;

FIGS. 5A-5B are simplified flow diagrams illustrating potential flowsand activities associated with providing PSM enhancements in accordancewith one potential embodiment of the communication system;

FIGS. 6A-6B are simplified flow diagrams illustrating other potentialflows and activities associated with providing PSM enhancements inaccordance with one potential embodiment of the communication system;and

FIG. 7 is a simplified flow diagram illustrating yet other potentialflows and activities associated with providing PSM enhancements inaccordance with one potential embodiment of the communication system.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

Overview

A method is provided in one example embodiment and may includedetermining that a periodic timer for a user equipment (UE) is about toexpire; communicating to an application service, prior to expiration ofthe periodic timer for the UE, an indication associated with anavailability of the UE to receive data from the application service; andcommunicating the data from the application service to the UE uponreceiving the indication. In some cases, the method can includeregistering, by the application service, to receive the indication froma Mobility Management Entity (MME) or a serving General Packet RadioService (GPRS) support node (SGSN), wherein the registering is performedvia a service capability exposure function (SCEF) in communication withthe MME or the SGSN and the application service. In some instances, theregistering can include subscribing by the application service to anevent trigger for the MME or the SGSN.

In some cases, the method can include configuring a mobile reachabilitytimer for the MME or the SGSN, where the mobile reachability timer isassociated with the event trigger and the periodic timer for the UE. Insome instances, the periodic timer can be associated with a TrackingArea Update (TAU) timer or a Routing Area Update (RAU) timer for the UE.In still some cases communicating the data to the UE can include pagingthe UE by the MME or the SGSN to receive the data from the applicationservice and in other cases data can be communicated to the UE withoutpaging the UE.

Another method is provided in another example embodiment and may includedeactivating, by a MME or a SGSN a power saving mode (PSM) for a userequipment (UE); communicating an indication to an application service,upon deactivation of the PSM for the UE, that the UE is available toreceive data; and communicating the data to the UE from the applicationservice upon receiving the indication. In some cases, the other methodcan include subscribing, by the application service, to a trigger forthe MME or the SGSN, wherein the trigger is associated with one or moreoperations to be performed by the MME or the SGSN to perform thedeactivating. In some instances, the subscribing is performed via aService Capability Exposure Function in communication with theapplication service and the MME or the SGSN.

In still some cases, the other method can include receiving, by the MMEor the SGSN, an indication of a Tracking Area Update (TAU) or a RoutingArea Update (RAU) for the UE. In some instances, the deactivating can beperformed after receiving the indication of the TAU or the RAU for theUE. In still some cases, the other method can include activating the PSMfor the UE upon completion of the data being communicated to the UE. Insome instances, the activating can include communicating a time to theUE associated with a Tracking Area Update (TAU) timer or a Routing AreaUpdate (RAU) timer.

Example Embodiments

Turning to FIG. 1, FIG. 1 is a simplified block diagram illustrating acommunication system 10 to facilitate providing power saving mode (PSM)enhancements in a network environment according to one embodiment of thepresent disclosure. This particular configuration may be tied to the 3rdGeneration Partnership Project (3GPP) Evolved Packet System (EPS)architecture, also sometimes referred to as the Long-term Evolution(LTE) EPS architecture. Alternatively, the depicted architecture may beapplicable to other environments equally.

The example architecture of FIG. 1 may include an end user operatinguser equipment (UE) 12 and a packet data network (PDN) gateway (PGW) 14,which may have a logical connection to a serving gateway (SGW) 16. Alsoprovided are a home subscriber server (HSS) 18, a 3GPP Authentication,Authorization and Accounting (AAA) element 20, a Mobility ManagementEntity (MME) 30, an evolved Node B (eNodeB) 32, a serving General PacketRadio Service (GPRS) support node (SGSN) 34, a Service CapabilityExposure Function (SCEF) 40, one or more Application Service(s) 42 and aNode B/Radio Network Controller (NodeB/RNC) 56. SGW 16 also has alogical connection to eNodeB 32, MME 30 and to SGSN 34. Both SGW 16 andPGW 14 can interface with a Policy and Charging Rules Function (PCRF)22, which may also interface with an Application Function (AF) 52. Alsoshown in FIG. 1 is an internet 50.

As used herein in this Specification, the terms ‘user equipment,’‘mobile node’, ‘user’ and ‘subscriber’ are interchangeable. As furtherused herein in this Specification, the terms ‘eNodeB’ and ‘eNB’ can beused interchangeably.

Each of the elements of FIG. 1 may couple to one another through simpleinterfaces (as illustrated) or through any other suitable connection(wired or wireless), which provides a viable pathway for networkcommunications. Additionally, any one or more of these elements may becombined or removed from the architecture based on particularconfiguration needs. For example, communication system 10 may include aconfiguration capable of transmission control protocol/Internet protocol(TCP/IP) communications for the transmission or reception of packets ina network. Communication system 10 may also operate in conjunction witha user datagram protocol/IP (UDP/IP) or any other suitable protocolwhere appropriate and based on particular needs.

In more general terms, 3GPP defines the Evolved Packet System (EPS) asspecified in Technical Specification (TS) 23.401, TS 29.272, etc. TheEPS generally consists of UE access networks and an Evolved Packet Core(EPC). Access networks may be 3GPP radio access networks, as shown inFIG. 1, including legacy access networks such as GSM EDGE Radio AccessNetwork (GERAN), Universal Mobile Telecommunications Systems (UMTS)Terrestrial Radio Access Network (UTRAN), also known as 3G, or LTEaccess networks such as Evolved UTRAN (E-UTRAN), also known as 4G/LTE orLTE-Advanced (LTE-A), or they may be non-3GPP IP access networks such asdigital subscriber line (DSL), Cable, WiMAX, WiFi, or the Internet. Invarious embodiments, NodeB/RNC 56 may provide cellular coverage for 2Gand/or 3G radio access networks (RANs) (e.g., UTRAN, GERAN).

In general, UE 12 can be associated with a client, customer or devicewishing to initiate a flow in communication system 10 via some network.The terms ‘user equipment’, ‘mobile node’, ‘end user’, ‘and ‘subscriber’are inclusive of devices used to initiate a communication, such as acomputer, a parking meter, a power meter, a personal digital assistant(PDA), a laptop or electronic notebook, a cellular telephone, ani-Phone®, i-Pad®, a Google® Droid® phone, an IP phone, or any otherdevice, component, element, or object capable of initiating voice,audio, video, media, and/or data exchanges within communication system10. UE 12 may also be inclusive of a suitable interface to the humanuser such as a microphone, a display, a keyboard, or other terminalequipment. UE 12 may also be any device that seeks to initiate acommunication on behalf of another entity or element such as a program,a database, or any other component, device, element, or object capableof initiating an exchange within communication system 10. Data orinformation, as used herein in this Specification, refers to any type ofnumeric, voice, video, media, or script data or information, or any typeof source or object code, or any other suitable information in anyappropriate format that may be communicated from one point to another.In certain embodiments, UE 12 may have a bundled subscription fornetwork access and services (e.g., voice, data, etc.), which may beprovided by a service provider and/or network operator via ApplicationService(s) 42. IP addresses can be assigned using dynamic hostconfiguration protocol (DHCP), Stateless Address Auto-configuration,default bearer activation, etc., or any suitable variation thereof.

Among other things, MME 30 may provide tracking area list management,idle mode UE tracking, bearer activation and deactivation, servinggateway and packet data network gateway selection for UEs andauthentication services. As shown in FIG. 1, MME 30 may be incommunication with SGSN 34, eNodeB 32, HSS 18 and SGW 16. In general,eNodeB 32 is responsible for selecting an MME for user equipment,managing radio resources, and making handover decisions for userequipment for E-UTRAN access networks. NodeB/RNC 56 may provide similarfunctions for user equipment for UTRAN and/or GERAN access networks. HSS18 may include one or more databases containing user-related andsubscription-related information. HSS 18 may perform functionalitiessuch as mobility management, call and session establishment support,user authentication and access authorization for 3GPP access. SGW 16 isa data plane element that can route and forward user data packets, whilealso acting as a mobility anchor for the user plane during inter-eNodeBhandovers and as an anchor for mobility between LTE and other 3GPPtechnologies. SGW 16 may further be in communication with PGW 14. SGSN34 may provide access and similar functions as MME 30 for legacy UMTSnetwork devices. For example, UE on the GERAN can communicate throughthe SGSN to the SGW or the PGW, which can include a gateway GPRS supportnode (GGSN) to support communication with legacy systems.

Given the similarity of operation of MME 30 (for 4G access networks) andSGSN 34 (for 2G/3G access networks), operations, activities, functions,flows, etc. described herein for communications system 10 may beperformed similarly by MME 30 and SGSN 34; and, in some cases, MME 30and SGSN 34 can be referred to collectively using the label ‘MME/SGSN’.

PGW 14 may provide Internet protocol (IP) connectivity access network(IP-CAN) session connectivity for UEs (e.g., UE 12) to one or moreexternal packet data networks (PDNs), such as, for example, internet 50.PGW 14 may also serve as policy enforcement points to manage QoS,online/offline flow-based charging, data generation, deep-packetinspection and intercept.

PCRF 22 may be in communication with PGW 14, SGW 16, and Applicationfunction (AF) 52. PCRF 22 may aggregate information to and from thenetwork, operational systems, and other sources in real-time, supportingthe creation of policy charging and control (PCC) rules and thenautomatically making policy decisions for each subscriber such as, forexample, quality of service (QoS) level decisions and charging ruledecisions. PCRF 22 can be configured to use user-related andsubscription-related information as a basis for the policy and chargingcontrol decisions. In some embodiments, PCRF 22 may determine PCC rulesbased on an application or service described to the PCRF fromApplication Function (AF) 52.

3GPP AAA element 20 is a network element responsible for accounting,authorization and authentication functions for UE 12. For AAAconsiderations, 3GPP AAA element 20 may provide a mobile node IP addressand the accounting session identification and other mobile node statesin appropriate messaging (e.g., via access-Request/access-Responsemessages). Authentication refers to the process where an entity'sidentity is authenticated, typically by providing evidence that it holdsa specific digital identity such as an identifier and the correspondingcredentials. The authorization function determines whether a particularentity is authorized to perform a given activity, typically inheritedfrom authentication when logging on to an application or service.Authorization may be determined based on a range of restrictions, forexample time-of-day restrictions, or physical location restrictions, orrestrictions against multiple accesses by the same entity or user.Accounting refers to the tracking of network resource consumption byusers for the purpose of capacity and trend analysis, cost allocation,billing, etc. In various embodiments, communication system 10 may beprovisioned with other AAA services and/or AAA servers, which mayprovide AAA considerations for the system.

Application Service(s) 42 may be provided in a service provider and/ornetwork operator domain external to the 3GPP domain elements ofcommunication system 10 (e.g., PGW 14, SGW 16, MME 30, etc.). In variousembodiments, Application Service(s) can be used to provision variousvalue added services (e.g., voice, data, etc.) that may be provided toUE by a service provider and/or network operator. In variousembodiments, operation of Application Service(s) 42 may be enabled usingone or Application Programming Interface (API) procedure calls asconfigured by a service provider and/or network operator for ApplicationService(s) 42 and/or SCEF 40. The API procedure calls may becommunicated to SCEF 40 via one or more API interface(s).

In general terms, Service Capability Exposure Function (SCEF) 40 mayprovide a generic framework for third party applications (e.g.,Application Service(s) 42) provided by a network operator and/or serviceprovider to access 3GPP network capabilities via what 3GPP defines to beexternal interfaces (e.g., Sh, Rx, etc.). The SCEF framework was createdto address 3GPP Release 13 (Rel-13) Service Exposure requirements. Otherdetails of the SCEF framework are described in 3GPP Technical Report(TR) 23.708.

Also provided in the architecture of FIG. 1 is a series of interfaces,which can offer mobility, policy control, AAA functions and/or chargingactivities (offline and online) for various network elements. Forexample, interfaces can be used to exchange point of attachment,location, and/or access data for one or more end users, for example, auser operating UE 12. Resource, accounting, location, access networkinformation, network address translation (NAT) control, etc. can beexchanged using a remote authentication dial in user service (RADIUS)protocol or any other suitable protocol where appropriate. Otherprotocols that can be used in communication system 10 can includeDIAMETER-based protocols, a service gateway interface (SGI), a terminalaccess controller access-control system (TACACS), TACACS+, Proxy MobileIP version 6 (PMIPv6), Proxy Mobile IP version 4 (PMIPv4), ExtensibleMessaging and Presence Protocol (XMPP), General Packet Radio Service(GPRS) Tunneling Protocol (GTP), GTP version 2 (GTPv2), Generic RouteEncapsulation (GRE), etc.

As shown in FIG. 1, a DIAMETER-based interface, Rx, may be maintainedbetween Application Function (AF) 52 and PCRF 22 for communicatingsubscriber information between IP services provided by a serviceprovider and PCRF 22. In various embodiments, the Rx interface can beDIAMETER-based or DIAMETER-based from the PCRF and representationalstate transfer (also referred to generally as ‘RESTful’) ExtensibleMarkup Language (XML) over Hypertext Transfer Protocol (HTTP) from theAF through a DIAMETER to RESTful Rx protocol converter (not shown). Invarious embodiments, IP services can include an IP multimedia subsystem(IMS) to provide IP multimedia services to subscribers. PCRF 22 mayprovision policy charging and control (PCC) rules for PGW 14 using aDIAMETER-based Gx/Sd interface and PGW 14 may communicate subscriberinformation to PCRF 22 over the Gx/Sd interface. A 3GPP standards-basedor proprietary interface may be provisioned between SCEF 40 and MME 30.A 3GPP standards-based or proprietary interface may also be provisionedbetween SCEF 40 and SGSN 34.

Communication system 10 may be configured with additional DIAMETER-basedinterfaces to manage policy and control between various elements of thesystem 10. For example, DIAMETER-based interface Gxc may be maintainedbetween the PCRF 22 and SGW 16. Further DIAMETER-based interfaces mayinclude SWx (interfacing 3GPP AAA element 20 and the HSS 18). Variousadditional interfaces may include an S6a interface between HSS 18 andMME 30; an S6d interface between HSS 18 and SGSN 34; an S6b interfacebetween 3GPP AAA element 20 and PGW 14; an S6m interface between SCEF 40and HSS 18; an S5/S8 interface between SGW 16 and PGW 14; and an S1-MMEinterface between MME 30 and eNodeB 32. Other signaling interfaces areillustrated between various components of FIG. 1, according to 3GPPstandards, which are not discussed in detail for purposes of brevity.

Before detailing further operations and infrastructure of variouselements of FIG. 1, certain contextual information is provided to offeran overview of some problems that may be encountered in providing PSMenhancements in a network environment. Such information is offeredearnestly and for teaching purposes only and, therefore, should not beconstrued in a way to limit the broad applications for the presentdisclosure.

In 3GPP Release 12 (Rel-12), a UE Power saving mode (PSM) feature wasintroduced. This feature allowed a PSM capable UE to enter a statesimilar to power-off while retaining its registration with the network.A PSM capable UE can deactivate its Access Stratum functions and canstop all idle mode procedures in a PSM state but can continue to run anyNAS timers that may apply such as periodic tracking area update (TAU) orrouting area update (RAU) timers. This implies that the UE is notavailable for mobile terminating (MT) services such as data transfer orsignaling. However, upon exiting the PSM state, the UE need notre-attach or re-establish packet data network (PDN) connections and canthereby achieves reduction in radio and core network signaling. Mobileoriginating activity may be resumed anytime by the UE exiting the PSMstate.

In general, user equipment can be in PSM mode for any amount of timeranging on the order of seconds to hours. The MME/SGSN servicing a givenPSM capable UE is aware of an Active Time granted to the UE and, duringa PSM state for the UE, immediately rejects all downlink communicationwhich requires the UE to be paged. Such rejections can span a number ofinterfaces such as SGs between the MME and a Visitor Location Register(VLR), SGd between the MME and a Short Message Service Center (SMSC) andS11/S4 between the MME/SGSN the SGW. In the case of S11 signaling, aGTPv2 rejection cause code #90 (UE UNREACHABLE) is communicated from theMME to the SGW when the UE is a PSM state. This cause code is also usedfor normal cases when the MME can't reach the UE for downlinktransmissions, for example, due to UE's battery abruptly being pulledoff (e.g., detach procedures aren't executed properly). Accordingly,upstream nodes (e.g., SGW, PGW, etc. involved in downlink communicationsto UE) can't distinguish why a given UE is unreachable.

Additionally, Application Services (AS) accessing a PSM capable UE donot have exposure to network-based states of the UE and may attempt tosend mobile terminated (MT) to the UE when it is in a PSM state. Suchmobile terminated (MT) traffic may be frequently rejected for deliveryto UE by the MME/SGSN servicing the PSM capable UE. Packet drop for besteffort PDNs is quite normal in an LTE network. However, in the case of aPSM capable UE being in a PSM state, because the UE may be “unavailablefor paging” for extended duration, the following side-effects can beobserved:

A) The SGW may have to unnecessarily buffer data until exhausting itsre-try transmission strategy;

B) During such time, there may be unnecessary signaling between the SGWand the MME (e.g., S11 signaling), and between the SGW and the SGSN(e.g., S4 signaling); and/or

C) If a sending entity (e.g., AS) isn't made aware of a UE's PSM state,then, depending on the application layer protocol used between UE and AScommunications, the sending entity (e.g., AS) may continue to send MTdata which will aggravate signaling in the network.

In addition, the 3GPP network may need a mechanism to trigger the AS tore-deliver its originally intended data. These frequent exchanges do notadd value and may contribute to network congestion. There is a desire tosolve problems related to downlink reachability by equipmentmanufacturers, service providers, network operators, etc. for 3GPPRelease 13 (Rel-13), which is in development.

In accordance with various embodiments described herein, communicationsystem 10 can overcome the aforementioned shortcomings (and others) byproviding solutions that can include techniques for ApplicationService(s) 42 to subscribe to one or more triggers via SCEF 40 and MME30/SGSN 34, which can be used to provide Application Service(s) 42 withan awareness of when a given PSM capable UE can be reached via MME30/SGSN34 to receive mobile terminated (MT) data.

In various embodiments, the solutions provided by communication system10 can be provisioned using a first alternative in which, when data isto be communicated to a given PSM capable UE (e.g., UE 12), ApplicationService(s) 42 can subscribe to a “reachability event” trigger via SCEF40 to a given MME/SGSN serving the UE, say for example, MME 30 servingUE 12. The reachability event trigger can be used to signal toApplication Service(s) 42, when UE 12 is about to be available toreceive mobile terminated (MT) data (e.g., sending a notification thatthe “UE will be reachable shortly”). In various embodiments, SCEF 40 canquery HSS 18 to determine an MME/SGSN serving a given UE.

In various embodiments, the solutions provided by communication system10 can be provisioned using a second alternative in which, when data isto be communicated to a given UE (e.g., UE 12), Application Service(s)42 can “subscribe” to a “deactivate_PSM_at_UE_contact” trigger via SCEF40 towards MME 30/SGSN 34. For the second alternative, the term“subscribe” is meant to indicate that Application Service(s) 42 mayactivate functionality for MME 30/SGSN 34 to deactivate PSM for the UEupon MME 30 receiving a TAU or SGSN 34 receiving a RAU from the UE andMME 30/SGSN 34 informing Application Service(s) 42 via SCEF 40 that theUE is reachable or is about to be reachable for sending downlink data.For example, upon deactivating PSM for UE 12, MME 30 can informApplication Service(s) 42 via SCEF 40 that the Application Service(s)can initiate downlink (e.g., MT) data toward the UE. Following any MTcommunications, Application Service(s) 42 can “unsubscribe” to the“deactivate_PSM_at_UE_contact,” which will allow MME 30 to resume PSMfor UE 12.

For both the first and second alternatives, it is assumed that MME30/SGSN 34 and UE 12 are both aware of the PSM Active timer, and at theexpiry of PSM Active time, the UE enters a PSM state and hence is notreachable (e.g., not available) for any network initiated communication.As noted above, In various embodiments, SCEF 40 can query HSS 18 todetermine an MME/SGSN serving a given UE.

During operation for the first alternative, MME 30/SGSN 34 may monitor aperiodic TAU/RAU timer and PSM Active timer for UE 12, which may be thesame as a Mobile Reachable Timer (MRT) configured for MME 30/SGSN 34. Invarious embodiments, MME 30/SGSN 34 may send a notification for thereachability event trigger to Application Service(s) 42 indicating, inessence, that the UE “will be reachable shortly” (e.g., available toreceive data within a prescribed time window) either: A) upondetermining that the periodic TAU/RAU timer is about to expire or B)upon receipt of a UE initiated service request (SR) or TAU/RAU. Invarious embodiments, based on whatever MRT that MME 30/SGSN 34 isrunning, MME 30/SGSN 34 can derive when the UE is expected to perform anext periodic TAU/RAU. With that knowledge, MME 30/SGSN 34 can notifyApplication Service(s) 42 via SCEF 40 about an impending reachability ofthe UE just before the expiry of UE's periodic TAU/RAU timer.

In some embodiments, MME 30/SGSN 34 can inform Application Service(s) 42that it can initiate downlink data within a prescribed time window. Invarious embodiments, the prescribed time window can indicate when the UEis reachable for network initiated communication(s). In variousembodiments, the prescribed time window may be prescribed in a number‘X’ seconds. In various embodiments, the time window can be calculatedby MME 30/SGSN 34 and provided to Application Service(s) 42. In certainembodiments, MME 30/SGSN 34 can use the UE's periodic TAU/RAU timervalue and PSM Active Time to calculate the time window. Thus, in variousembodiments, MME 30/SGSN 34 can inform Application Service(s) 42 that itcan initiate downlink data within a prescribed time window if the UEperforms a normal TAU/RAU (e.g., due to a change in radio/core networkproperties) or if the UE performs an SR due to unexpected MO data.

In various embodiments, MME 30/SGSN 34 can also disable the trigger. Forexample, in some cases, the UE may no longer advertise PSM capabilities,in which cases the notifications/triggers may no longer be needed.Accordingly, various combinations may be possible in various embodimentsfor communicating mobile terminated (MT) data to UE 12 from ApplicationService(s) during operation including, but not limited to:

A) Application Service(s) 42 sends downlink data and correspondingly theSGW generates DDN towards the MME/SGSN:

-   -   i) If UE 12 becomes reachable (e.g., exits PSM state), MME        30/SGSN 34 can page the UE and UE can send a NAS service        request. MME 30/SGSN 34 can then establish the bearer data-path.    -   ii) Alternatively, if the periodic TAU/RAU timer expires, UE 12        can initiate a TAU request and MME 30/SGSN 34 can choose to use        the TAU/RAU received to establish the data-path on its own.    -   iii) In yet another alternative, if UE 12 has initiated NAS        service request, the data-path can be established as well.

B) When the data-path is established, Application Service(s) 42 mayresume communication with the UE.

While the “reachability event” trigger is subscribed to at the MME/SGSNserving a given UE, if the UE performs mobility TAU/RAU in anotherMME's/SGSN's area (e.g., the UE enters PSM and then comes out of the PSMin another MME's/SGSN's area), the source MME/SGSN can, in variousembodiments, send information about the event trigger (e.g., the ASidentity to which the corresponding event trigger needs to be deliveredto) as part of a mobility management (MM) context information element(IE) to the target MME/SGSN. The solution provided by the firstalternative for communication system 10 may provide a high likelihood ofMT data delivery to PSM enabled UE.

For the second alternative, as noted above, MME 30 and UE 12 are bothaware of the PSM Active timer and Application Service(s) 42 cansubscribe to the a ‘deactivate_PSM_at_UE_contact’ trigger via SCEF 40towards MME 30/SGSN 34. During operation, when Application Service(s) 42needs to send data to UE 12, Application Service(s) 42 can communicatethe ‘deactivate_PSM_at_UE_contact’ to MME 30. When UE 12 communicatesits TAU to MME 30, a corresponding Active timer may not be allocated tothe UE by MME 30 for at least the duration of the transfer of MT datafrom Application Service(s) 42. When an Active time is not allocated toUE 12, it may transition to an IDLE mode (e.g., EPS ConnectionManagement-IDLE (ECM-IDLE) mode) but may retain its Access Stratumfunctions, hence, making it available for paging (e.g., MT signaling)and consequently any MT data. Following deactivating PSM for UE 12, MME30, via SCEF 40, can send a notification to Application Service(s) 42indicting that UE 12 is reachable or will be reachable shortly toreceive mobile terminated (MT) data from the Application Service(s).

In various embodiments, once Application Service(s) 42 completes its MTdata communication towards UE 12 and if the Application Service(s) nolonger need the UE to remain active, Application Service(s) canunsubscribe to the ‘deactivate_PSM_at_UE_contact’ trigger (e.g.,subscribe via SCEF 40 to a trigger for MME 30 to enable PSM for UE 12 ina subsequent TAU). This will allow MME 30 to resume PSM for UE 12 at thenext normal or periodic TAU communication with the UE. In variousembodiments, this can help to avoid unnecessary wasting of battery inthe UE if the UE is not required for further data communication byApplication Service(s) 42. In various embodiments, subscribing via SCEF40 to a trigger for MME 30 to enable PSM for UE 12 in a subsequent TAUcan include providing an Active time to the UE, thereby enabling the UEto enter PSM upon expiry of the active time. In various embodiments, PSMcan be enabled/disabled in a UE by providing an appropriate value (e.g.,Active time) in the T3324 information element (IE) [as prescribed in3GPP TS 24.008 and TS 24.301] in Attach Accept messages, Tracking AreaUpdate Accept messages, etc. Similar functionality can be provided forSGSN 34 for 3G access networks.

It should be noted that the names for the triggers described for thefirst and second alternatives are provided for illustrative purposesonly and are not meant to limit the broad scope of the presentdisclosure for providing PSM enhancements. Any trigger name oridentifier can be provisioned for communication system 10 to achieve thesolutions as provided by the first and second alternative and thus areclearly within the scope of the present disclosure.

Accordingly, the solution provided by communication system 10 solves theproblem of downlink data loss due to 3GPP Rel-12 PSM feature for UEs. Inaddition, the solution provides step towards changing a programmingparadigm for devices with high latency communication wherein rather thansending downlink data to such devices assuming the data to be delivered,applications ask for device reachability before doing so.

Turning to FIG. 2, FIG. 2 is a simplified block diagram illustratingadditional details associated with one potential embodiment ofcommunication system 10. FIG. 2 includes PGW 14, SGW 16, HSS 18, 3GPPAAA element 20, PCRF 22, MME 30, eNodeB 32, SGSN 34, SCEF 40,Application Service(s) 42, Application Function 52 and NodeB/RNC 56 ofcommunication system 10. Each of these elements may include a respectiveprocessor 44 a, 44 b, 44 c, 44 d, 44 e, 44 f, 44 g, 44 h, 44 k, 44 m, 44n, 44 p and a respective memory element 46 a, 46 b, 46 c, 46 d, 46 e, 46f, 46 g, 46 h, 46 k, 46 m, 46 n, 46 p. As shown in FIG. 2, MME 30, SGSN34, SCEF 40 and Application Service(s) 42 may each include a respectivePSM coordination module 64 a-64 d and a respective PSM trigger storage66 a-66 d. Also shown in FIG. 2 is UE 12 and internet 50.

In various embodiments, each of MME 30, SGSN 34, SCEF 40 and ApplicationService(s) 42 may be provisioned and/or configured with one or moreevent triggers via respective PSM trigger storage 66 a-66 d, to whichApplication Service(s) 42 can subscribe to be notified of UEavailability to receive traffic from Application Service(s) 42. Invarious embodiments, the event triggers can also be provisioned in oneor more databases, combination thereof or the like that may beprovisioned in each of MME 30, SGSN 34, SCEF 40 and ApplicationService(s) 42, which can overlap or be included with each respectivememory element 46 f, 46 h, 46 k, 46 m and/or each respective PSMcoordination module 64 a, 64 b, 64 c, 64 d. In various embodiments, theevent triggers can be stored and related to UE based on one or more UEidentifiers, such as, for example International Mobile SubscriberIdentity (IMSI) identifying a subscriber associated with a given UE,Temporary Mobile Subscriber Identity (TMSI), Mobile StationInternational Subscriber Directory Number (MSISDN), Anonymous CustomerReference (ACR), combinations thereof or the like. In some cases, an ACRcan be used as to identify a subscriber if other identifiers, such asMSISDN, for example, are prevented due to privacy concerns.

Hence, appropriate software and/or hardware is being provisioned in PGW14, SGW 16, HSS 18, 3GPP AAA element 20, PCRF 22, MME 30, eNodeB 32,SGSN 34, SCEF 40, Application Service(s) 42, Application Function 52 andNodeB/RNC 56 in order to facilitate providing PSM enhancements in thenetwork environment of communication system 10. Note that in certainexamples, certain databases can be consolidated with memory elements (orvice versa), or the storage can overlap/exist in any other suitablemanner.

In one example implementation, PGW 14, SGW 16, HSS 18, 3GPP AAA element20, PCRF 22, MME 30, eNodeB 32, SGSN 34, SCEF 40, Application Service(s)42, Application Function 52 and NodeB/RNC 56 are network elements, whichare meant to encompass network appliances, servers, routers, switches,gateways, bridges, loadbalancers, firewalls, processors, modules, or anyother suitable device, component, element, or object operable toexchange information that facilitates or otherwise helps to provide forPSM enhancements (e.g., for a network as illustrated in FIG. 1). Inother embodiments, these operations and/or features may be providedexternal to these elements or included in some other network device toachieve this intended functionality. Alternatively, one or more of theseelements can include software (or reciprocating software) that cancoordinate in order to achieve the operations and/or features, asoutlined herein. In still other embodiments, one or more of thesedevices may include any suitable algorithms, hardware, software,components, modules, interfaces, or objects that facilitate theoperations thereof. This may be inclusive of appropriate algorithms andcommunication protocols that allow for the effective exchange of data orinformation. In some embodiments, DIAMETER routing agents (DRAs) mayinterface between network elements in order to provide DIAMETER routingprocedures for DIAMETER-based messages.

In regards to the internal structure associated with communicationsystem 10, each of PGW 14, SGW 16, HSS 18, 3GPP AAA element 20, PCRF 22,MME 30, eNodeB 32, SGSN 34, SCEF 40, Application Service(s) 42,Application Function 52 and NodeB/RNC 56 can include memory elements [asshown in FIG. 2] for storing information to be used in achieving PSMcoordination activities, as outlined herein. Additionally, each of thesedevices may include a processor [as shown in FIG. 2] that can executesoftware or an algorithm to perform the PSM coordination activities asdiscussed in this Specification. These devices may further keepinformation in any suitable memory element [e.g., random access memory(RAM), read only memory (ROM), an erasable programmable read only memory(EPROM), application specific integrated circuit (ASIC), etc.],software, hardware, or in any other suitable component, device, element,or object where appropriate and based on particular needs. Any of thememory items discussed herein should be construed as being encompassedwithin the broad term ‘memory element’.

In various embodiments, information being tracked or sent to PGW 14, SGW16, HSS 18, 3GPP AAA element 20, PCRF 22, MME 30, eNodeB 32, SGSN 34,SCEF 40, Application Service(s) 42, Application Function 52 andNodeB/RNC 56 could be provided in any database, register, control list,cache, or storage structure: all of which can be referenced at anysuitable timeframe. Any such storage options may be included within thebroad term ‘memory element’ as used herein. Similarly, any of thepotential processing elements, modules, and machines described hereinshould be construed as being encompassed within the broad term‘processor’. Each of the network elements and/or user equipment (e.g.,mobile nodes) can also include suitable interfaces for receiving,transmitting, and/or otherwise communicating data or information in anetwork environment.

Note that in certain example implementations, the PSM coordinationtechniques as outlined herein may be implemented by logic encoded in oneor more tangible media, which may be inclusive of non-transitory media(e.g., embedded logic provided in an ASIC, in digital signal processing(DSP) instructions, software [potentially inclusive of object code andsource code] to be executed by a processor, or other similar machine,etc.). In some of these instances, memory elements [as shown in FIG. 2]can store data or information used for the operations described herein.This includes the memory elements being able to store software, logic,code, or processor instructions that are executed to carry out theactivities described herein.

A processor can be a hardware processor and can execute any type ofinstructions associated with the data or information to achieve the PSMcoordination operations detailed herein. In one example, the processors[as shown in FIG. 2] could transform an element or an article (e.g.,data) from one state or thing to another state or thing. In anotherexample, the activities outlined herein may be implemented with fixedlogic or programmable logic (e.g., software/computer instructionsexecuted by a processor) and the elements identified herein could besome type of a programmable processor, programmable digital logic (e.g.,a field programmable gate array (FPGA), a DSP processor, an EPROM, anelectrically erasable PROM (EEPROM)) or an ASIC that includes digitallogic, software, code, electronic instructions, or any suitablecombination thereof.

In order to further detail the appropriate operations to achieve theteachings of the present disclosure, reference is now made to FIGS. 3-4.FIG. 3 is a simplified flow diagram 300 illustrating example flows andactivities associated with typical PSM signaling between a given PSMcapable UE and a given MME. FIG. 4 is a simplified flow diagram 400illustrating example flows and activities associated with typical PSMsignaling for an application service. Such information is offeredearnestly and for teaching purposes only and, therefore, should not beconstrued in any way to limit the broad applications for the presentdisclosure.

Turning to FIG. 3, at 302, 304 the PSM capable UE communicates an attachrequest to the MME via a particular eNB. At 306, the UE is attached tothe MME and at 308 the UE enters an IDLE mode. At 310, the UE starts anactive timer, for an Active time which has been granted by the MME. TheUE typically requests an Active time for PSM during an attach and/ortracking area update (TAU). At 312, the MME starts a Mobile ReachableTimer (MRT) (e.g., equal to the value of the Active time). At 314, theActive timer expires for the UE and the UE enters a PSM state; shuttingoff its access stratum functions while its Non-Access Stratum (NAS)timers for its logical interface with the MME continue to run. At 316,the MRT timer for the MME expires. As noted, upon the UE entering thePSM state, the UE becomes unavailable for mobile terminated (MT)signaling and/or data. At 318, it is assumed that mobile originating(MO) signaling/data needs to be sent for the UE, in which case the UEexits the PSM state, enables Access Stratum functions and initiates aservice request (SR) and/or tracking area update (TAU) toward the MME.FIG. 3 illustrates that the UE, upon entering the PSM state, is notimmediately reachable for mobile terminated services. Rather, the UE ina PSM state is typically only available for such services for the periodof the Active time following an MO event, such as, for example a TAU.

Turning to FIG. 4, FIG. 4 illustrates the rejection of data from a givenApplication Service (AS), which typically occurs when a PSM capable UEis in a PSM state. At 402, 404, 406 the PSM capable UE communicates anattach request to the MME via a particular eNB and attaches to the MMEsimilar 302, 304, 306 as shown in FIG. 3. At 408, the UE starts anactive timer, for an Active time which has been granted to the UE by theMME. At 410, the MME starts a Mobile Reachable Timer (MRT) (e.g., equalto the value of the Active time). At 412, the Active timer expires forthe UE and the UE enters a PSM state. While the UE is in the PSM state,it is unavailable for mobile terminated (MT) signaling from the MME, asshown at 414.

It is assumed that the Application Service desires to communicate MTdata to the UE at 416, which is communicated to a given PGW. The PGWconverts the MT data to S5/GTP-U (GTP user plane) data, which iscommunicated to a given SGW at 418. At 420, the SGW, in turn, initiatesan S11 downlink data notification (DDN) request to the MME. Because theMME is unable to relay MT signaling/data to the UE, which is in the PSMstate, the MME responds to the request with a DDN rejection at 422.Following the rejection, at 424 the SGW drops the packet(s) associatedwith the MT data from the Application Service. Thus, as shown in FIG. 4,current techniques for handling downlink reachability typically involvedropping of UE packets/data.

Turning to FIGS. 5A-5B, FIGS. 5A-5B are simplified flow diagrams 500illustrating example flows and activities associated with providing PSMenhancements in a network environment in accordance with one potentialembodiment of communication system 100. In general, FIGS. 5A-5Billustrate example flows and activities associated with embodiments fora first sub-alternative to the first alternative of the solutionsprovided by communication system 10 in which MME 30 may be configured tocommunicate an indication to Application Service(s) (AS) 42 that UE 12is reachable or is about to be reachable within a prescribed time windowupon MME 30 determining that a periodic TAU timer for UE 12 is about toexpire. It should be noted that although the flows and activities shownin FIGS. 5A-5B are illustrated with respect to E-UTRAN communications,the flows and activities can be equally applied to GERAN/UTRANcommunications via NodeB/RNC 56 and SGSN 34.

At 502, UE 12 communicates an attach request to eNB 32, whichcommunicates the attach request to MME 30 at 504. At 506, UE 12 isattached to MME 30. At 508, UE 12 enters an ECM-IDLE mode. At 510, theActive timer for UE 12 is started and at 512 the Mobile Reachable Timer(MRT) for MME 30 is started. At 514, the Active timer for UE 12 expiresand the UE enters a PSM state; shutting off its access stratum functionswhile its Non-Access Stratum (NAS) timers for the logical interface withMME 30 continue to run. At 516, UE 12 is unavailable for mobileterminated (MT) signaling and/or data from MME 30.

At 518, it is assumed that Application Service(s) 42 desires to sendmobile terminated (MT) data to UE 12. At 520, 522, ApplicationService(s) 42 registers to a UE reachability indication (e.g., anavailability indication) to be received from MME 30 to indicate when orapproximately when (e.g., within a prescribed window) UE 12 is reachableto receive data from Application Service(s) 42. The registration may becommunicated directly to MME 30 via SCEF 40, as shown at 522. In variousembodiments, SCEF 40 can query HSS 18 to determine the MME (MME 30)serving UE 12, though this is not shown in FIG. 5A in order toillustrate other features of communication system 10. At 524, 526, MME30 may respond to the request via SCEF 40 with an indication that theregistration was a success. In various embodiments, the registering caninclude Application Service(s) 42 subscribing to a “reachability event”trigger for MME 30, which, upon triggering by MME 30, can be used toindicate that UE 12 is reachable or is about to become reachable toreceive data from Application Service(s) 42.

Continuing to FIG. 5B, at 528, MME 30 determines that a periodic TAUtimer for UE 12 is about to expire (e.g., based on the MRT timer startedat 512 that may be about to expire). Based on the determination, MME 30communicates an indication to Application Service(s) 42 via SCEF 40 at530, 532 that indicates that the UE is reachable or is about to becomereachable within a prescribed time window.

Two options for communicating mobile terminated (MT) data to UE 12 areshown in FIG. 5B. For a first option, Application Service(s) 42 sendsthe data to the UE before the UE enters an ECM-CONNECTED mode. The firstoption is illustrated at 540-550. For a second option, ApplicationService(s) 42 sends the data to the UE after the UE enters anECM-CONNECTED mode. The second option is illustrated at 562-564.

For the first option, it is assumed that UE 12 exits its PSM state at540, but a data path with MME 30 is not be established beforeApplication Service(s) 42 communicates the MT data to PGW 14 at 542(e.g., Application Service(s) 42 generates one or more messagesincluding the data to communicate to PGW 14). At 544, PGW 14 convertsthe MT data to S5/GTP-U data, which is communicated to SGW 16. At 546,SGW 16 communicates an S11 downlink data notification (DDN) request toMME 30. At 548, 550 MME 30 initiates S1 paging to UE 12 via eNB 32 tocause the UE to initiate a NAS service request as shown at 560 leadingto data path establishment with MME 30. Following the data pathestablishment, SGW 16 may convert the S5/GTP-U data to S1-U data, whichmay be communicated to eNB 32 at 566. At 568, eNB 32 communicates thedata to UE 12 utilizing Packet Data Convergence Protocol (PDCP) datadelivery techniques.

For the second option, it is assumed that UE 12 either initiates a NASservice request (e.g., due to unexpected MO data) or tracking areaupdate as shown at 560 leading to data path establishment with MME 30.For this option, Application Service(s) 42 communicates the MT data toPGW 14 at 562 (e.g., Application Service(s) 42 generates one or moremessages including the data to communicate to PGW 14). At 564, PGW 14converts the MT data to S5/GTP-U data, which is communicated to SGW 16.Because a data path is established between UE 12 and MME 30 for thesecond option, no paging may be necessary and SGW 16 may convert theS5/GTP-U data to S1-U data, which may be communicated to eNB 32 at 566.At 568, eNB 32 communicates the data to UE 12 utilizing Packet DataConvergence Protocol (PDCP) data delivery techniques. It should beunderstood that although the flows and activities shown in FIGS. 5A-5Bare illustrated with respect to E-UTRAN communications, the flows andactivities can be equally applied to GERAN/UTRAN communications viaNodeB/RNC 56 and SGSN 34 for periodic RAU timers.

Turing to FIGS. 6A-6B, FIGS. 6A-6B are simplified flow diagrams 600illustrating other example flows and activities associated withproviding PSM enhancements in a network environment in accordance withone potential embodiment of the communication system. In general, FIGS.6A-6B illustrates example flows and activities associated withembodiments for a second sub-alternative to the first alternative of thesolutions provided by communication system 10 in which MME 30 may beconfigured to communicate an indication to Application Service (AS) 42that UE 12 is reachable or is about to be reachable within a prescribedtime window upon MME 30 receiving mobile originated (MO) data from UE 12for a UE initiated service request or TAU. Thus, the flows andactivities shown in flow diagrams 600 differ from the example flows andactivities shown in FIGS. 5A-5B primarily with regard to the timing inwhich MME 30 communicates an indication to Application Service(s) (AS)42 indicating that UE 12 is reachable or is about to be reachable byApplication Service(s) 42. In FIGS. 6A-6B, MME 30 communicates anindication to Application Service(s) 42 that UE 12 is reachable or isabout to be reachable after receiving a UE initiated service request orTAU as opposed to FIGS. 5A-5B, which illustrates that MME 30communicates an indication that UE 12 is reachable or is about to bereachable upon determining that the periodic TAU timer for UE 12 isabout to expire.

Accordingly, the flows and activities shown at 602-626 for FIGS. 6A-6Bare similar to the corresponding flows and activities shown at 502-526for FIGS. 5A-5B. At 630 for FIG. 6B UE 12 exits its PSM state. At 632, aUE initiated service request or TAU is communicated from UE 12 to MME30, which leads to data path establishment between UE 12 and MME 30 alsoat 632 for the UE 12 ECM-CONNECTED mode. At 634, 636, MME 30communicates a notification to Application Service(s) 42 via SCEF 40indicating that UE 12 is reachable. In various embodiments, thenotification may include an indication of a time window for which UE 12is reachable. For example, as MME 30 is tracking the PSM-related Activetime associated with the UE, it may be capable of including in any UEreachable communications with Application Service(s) 42 the time windowin which the Application Service(s) 42 may restart communications withthe UE. In some embodiments, including the time window of when the UE isreachable in communications with Application Service(s) 42 may providean advantage of allowing Application Service(s) 42 to space-out or varycommunications with the UE according to the time window.

At 638 mobile terminated (MT) data from Application Service(s) 42 may becommunicated to PGW 14 (e.g., Application Service(s) 42 generates one ormore messages including the data to communicate to PGW 14). At 640, PGW14 converts the MT data to S5/GTP-U (GTP user plane) data, which iscommunicated to SGW 16. Because UE 12 is an ECM-CONNECTED mode, SGW 16converts the S5/GTP-U data to S1-U data, which is communicated to eNB 32at 642. At 644, eNB 32 communicates the data to UE 12 utilizing PacketData Convergence Protocol (PDCP) data delivery techniques. It should beunderstood that although the flows and activities shown in FIGS. 6A-6Bare illustrated with respect to E-UTRAN communications, the flows andactivities can be equally applied to GERAN/UTRAN communications viaNodeB/RNC 56 and SGSN 34 for periodic RAU timers.

Turning to FIG. 7, FIG. 7 is a simplified flow diagram 700 illustratingyet other example flows and activities associated with providing PSMenhancements in a network environment in accordance with one potentialembodiment of the communication system. FIG. 7 illustrates example flowsand activities associated with embodiments of the second alternative forthe solutions provided by communication system 10 in which ApplicationService(s) 42 indicate to MME 30 to deactivate PSM for UE 12 at a nexttracking area update (TAU) in order to communicate MT data fromApplication Service(s) 42 to UE 12.

At 702, it is assumed that UE 12 is attached to MME 30 and at 704 thatUE 12 enters an ECM-IDLE mode. At 706, the Active timer for UE 12 isstarted and at 708 the Mobile Reachable Timer (MRT) for MME 30 isstarted. At 710, the Active timer for UE 12 expires and the UE enters aPSM state; shutting off its access stratum functions while itsNon-Access Stratum (NAS) timers for the logical interface with MME 30continue to run. At 712, UE 12 is unavailable for mobile terminated (MT)signaling and/or data from MME 30.

At 714, it is assumed that Application Service(s) 42 desires to senddata to UE 12. According to a particular embodiment, ApplicationService(s) 42 registers with MME 30 at 716, 718 to deactivate PSM for UE12 at the next TAU for UE 12. In various embodiments, the registeringcan include subscribing to a trigger toward MME 30 indicating todeactivate PSM for UE 12. As shown at 718, the registering is performedvia SCEF 40, which may communicate directly with MME 30 for theregistering.

At 720, it is assumed that UE 12 exits its PSM state. At 722, UE 12initiates a TAU procedure with MME 30 and MME 30, upon determining thatthe TAU for UE 12 has been received, deactivates PSM for UE 12 andre-establishes a data path with the UE. At 724, MME 30 communicates anindication to Application Service(s) 42 via SCEF 40 (at 726) indicatingthat the UE is reachable or is about to become reachable within aprescribed time window.

At 728 mobile terminated (MT) data from Application Service(s) 42 may becommunicated to PGW 14 (e.g., Application Service(s) 42 generates one ormore messages including the data to communicate to PGW 14). At 730, PGW14 converts the MT data to S5/GTP-U (GTP user plane) data, which iscommunicated to SGW 16. SGW 16 converts the S5/GTP-U data to S1-U data,which is communicated to eNB 32 at 732. At 734, eNB 32 communicates thedata to UE 12 utilizing Packet Data Convergence Protocol (PDCP) datadelivery techniques. In certain embodiments, MME 30 can re-activate orre-enable the PSM for UE 12 following the communication of MT data to UE12 from Application Service(s) 42. In various embodiments, ApplicationService(s) 42 can re-enable PSM for UE 12 upon completing its transferof data to UE and if Application Service(s) 42 no longer need UE 12 toremain active. In various embodiments, re-enabling PSM for UE 12 caninclude subscribing via SCEF 40 to a trigger for MME 30 to enable PSMfor UE 12 in a subsequent TAU can include providing an Active time tothe UE, thereby enabling the UE to enter PSM upon expiry of the activetime. In various embodiments, PSM can be enabled/disabled in a given UEby providing an appropriate value (e.g., Active time) in the T3324information element (IE) in an Attach Accept message and/or a TrackingArea Update Accept message communicated from MME 30 to UE 12. It shouldbe understood that although the flows and activities shown in FIG. 7 areillustrated with respect to E-UTRAN communications, the flows andactivities can be equally applied to GERAN/UTRAN communications viaNodeB/RNC 54 and SGSN 34 for periodic RAU timers.

Note that in this Specification, references to various features (e.g.,elements, structures, modules, components, steps, operations,characteristics, etc.) included in ‘one embodiment’, ‘exampleembodiment’, ‘certain embodiment’, ‘an embodiment’, ‘anotherembodiment’, ‘some embodiments’, ‘various embodiments’, ‘otherembodiments’, ‘certain embodiments’, ‘alternative embodiment’, and thelike are intended to mean that any such features are included in one ormore embodiments of the present disclosure, but may or may notnecessarily be combined in the same embodiments. Note also that a moduleas used herein in this Specification, can be inclusive of an executablefile comprising instructions that can be understood and processed on acomputer, and may further include library modules loaded duringexecution, object files, system files, hardware logic, software logic,or any other executable modules.

Note that with the examples provided above, as well as numerous otherexamples provided herein, interaction may be described in terms of two,three, or four network elements. However, this has been done forpurposes of clarity and example only. In certain cases, it may be easierto describe one or more of the functionalities of a given set of flowsby only referencing a limited number of network elements. It should beappreciated that communication system 10 (and its teachings) are readilyscalable and can accommodate a large number of components, as well asmore complicated/sophisticated arrangements and configurations.Accordingly, the examples provided should not limit the scope or inhibitthe broad teachings of communication system 10 as potentially applied toa myriad of other architectures.

It is also important to note that the steps in the appended diagramsillustrate only some of the possible signaling scenarios and patternsthat may be executed by, or within, communication system 10. Some ofthese steps may be deleted or removed where appropriate, or these stepsmay be modified or changed considerably without departing from the scopeof teachings provided herein. In addition, a number of these operationshave been described as being executed concurrently with, or in parallelto, one or more additional operations. However, the timing of theseoperations may be altered considerably. The preceding operational flowshave been offered for purposes of example and discussion. Substantialflexibility is provided by communication system 10 in that any suitablearrangements, chronologies, configurations, and timing mechanisms may beprovided without departing from the teachings provided herein.

Although the present disclosure has been described in detail withreference to particular arrangements and configurations, these exampleconfigurations and arrangements may be changed significantly withoutdeparting from the scope of the present disclosure. For example,although the present disclosure has been described with reference toparticular communication exchanges involving certain network flows, andsignaling protocols, communication system 10 may be applicable to otherexchanges, routing protocols, or routed protocols to provide PSMenhancements in a network environment. Moreover, although communicationsystem 10 has been illustrated with reference to particular elements andoperations that facilitate the communication process, these elements andoperations may be replaced by any suitable architecture or process thatachieves the intended functionality of communication system 10.

Numerous other changes, substitutions, variations, alterations, andmodifications may be ascertained to one skilled in the art and it isintended that the present disclosure encompass all such changes,substitutions, variations, alterations, and modifications as fallingwithin the scope of the appended claims. In order to assist the UnitedStates Patent and Trademark Office (USPTO) and, additionally, anyreaders of any patent issued on this application in interpreting theclaims appended hereto, Applicant wishes to note that the Applicant: (a)does not intend any of the appended claims to invoke paragraph six (6)of 35 U.S.C. section 112 as it exists on the date of the filing hereofunless the words “means for” or “step for” are specifically used in theparticular claims; and (b) does not intend, by any statement in thespecification, to limit this disclosure in any way that is not otherwisereflected in the appended claims.

What is claimed is:
 1. A method comprising: registering, by anapplication service, to receive an indication from a Mobility ManagementEntity (MME) or a serving General Packet Radio Service (GPRS) supportnode (SGSN), wherein the indication is associated with an availabilityof a user equipment (UE) to receive data from the application serviceand wherein the registering is performed via a service capabilityexposure function (SCEF); determining that a periodic timer for the UEis about to expire; communicating to the application service, prior toexpiration of the periodic timer for the UE, the indication associatedwith the availability of the UE to receive data from the applicationservice; and communicating the data from the application service to theUE upon receiving the indication.
 2. The method of claim 1, wherein theregistering includes subscribing by the application service to an eventtrigger for the MME or the SGSN.
 3. The method of claim 2, furthercomprising: configuring a mobile reachability timer for the MME or theSGSN, where the mobile reachability timer is associated with the eventtrigger and the periodic timer for the UE.
 4. The method of claim 2,wherein the periodic timer is associated with a Tracking Area Update(TAU) timer or a Routing Area Update (RAU) timer for the UE.
 5. Themethod of claim 2, wherein communicating the data to the UE includespaging the UE by the MME or the SGSN to receive the data from theapplication service.
 6. The method of claim 2, wherein communicating thedata to the UE includes communicating the data to the UE without pagingthe UE.
 7. One or more non-transitory tangible media encoding logic thatincludes instructions for execution by a processor, wherein theexecution causes the processor to perform operations, comprising:registering, by an application service, to receive an indication from aMobility Management Entity (MME) or a serving General Packet RadioService (GPRS) support node (SGSN), wherein the indication is associatedwith an availability of a user equipment (UE) to receive data from theapplication service and wherein the registering is performed via aservice capability exposure function (SCEF); determining that a periodictimer for the UE is about to expire; communicating to the applicationservice, prior to expiration of the periodic timer for the UE, theindication associated with the availability of the UE to receive datafrom the application service; and communicating the data from theapplication service to the UE upon receiving the indication.
 8. Themedia of claim 7, wherein the registering includes subscribing by theapplication service to an event trigger for the MME or the SGSN.
 9. Themedia of claim 8, wherein the execution causes the processor to performfurther operations, comprising: configuring a mobile reachability timerfor the MME or the SGSN, where the mobile reachability timer isassociated with the event trigger and the periodic timer for the UE. 10.The media of claim 8, wherein the periodic timer is associated with aTracking Area Update (TAU) timer or a Routing Area Update (RAU) timerfor the UE.
 11. The media of claim 8, wherein communicating the data tothe UE includes paging the UE by the MME or the SGSN to receive the datafrom the application service.
 12. The media of claim 8, whereincommunicating the data to the UE includes communicating the data to theUE after the UE enters a connected mode.
 13. A system comprising: atleast one memory element for storing data; and at least one processorfor executing instructions associated with the data, wherein theexecuting causes the system to perform operations, comprising:registering, by an application service, to receive an indication from aMobility Management Entity (MME) or a serving General Packet RadioService (GPRS) support node (SGSN), wherein the indication is associatedwith an availability of a user equipment (UE) to receive data from theapplication service and wherein the registering is performed via aservice capability exposure function (SCEF); determining that a periodictimer for the UE is about to expire; communicating to the applicationservice, prior to expiration of the periodic timer for the UE, theindication associated with the availability of the UE to receive datafrom the application service; and communicating the data from theapplication service to the UE upon receiving the indication.
 14. Thesystem of claim 13, wherein the registering includes subscribing by theapplication service to an event trigger for the MME or the SGSN.
 15. Thesystem of claim 14, wherein the executing causes the system to performfurther operations, comprising: configuring a mobile reachability timerfor the MME or the SGSN, where the mobile reachability timer isassociated with the event trigger and the periodic timer for the UE. 16.The system of claim 14, wherein the periodic timer is associated with aTracking Area Update (TAU) timer or a Routing Area Update (RAU) timerfor the UE.
 17. The system of claim 14, wherein communicating the datato the UE includes at least one of: paging the UE by the MME or the SGSNto receive the data from the application service; and communicating thedata to the UE after the UE enters a connected mode.